The Development Core is conceived in service to specific aims (2) SA2 and SA3.b. The core objectives are to (1) recruit and retain new researchers and investigators in the field of population research; (2) provide seed funds for the preparation and sustenance of larger projects?in particular, to facilitate accretion of preliminary results in service to applications for extramural funding; (3) help researchers maintain and acquire skills necessary to be at the vanguard of population research; and (4) foster ties?intellectual and research-specific?within a diverse population research community. We are very concerned about new population scientists, but our concept of human resource development is a capacious one: We are interested in skill renewal; recognize that skill sets may be uncorrelated or inversely correlated with experience as measured by time in rank;' and know that no one size fits all when it comes to training, skill acquisition, and the productive exploitation of this human capital across a career. We begin with the current and projected activities of this core?their logic for the unified scientific process?and, for each, how they articulate with (and, in many cases, leverage) institutional support, and then describe the administrative structure (3.4.3.b) that will co-ordinate the activities and thus add another level of infrastructural support.